Linux strictly refers to the Linux kernel, but is commonly used to describe the entire free software Unix-like operating system, also known as GNU/Linux, that is formed by combining the Linux kernel with the GNU libraries and tools. The first version of the Linux kernel was written by Linus Torvalds and released in 1991, combined with essential components from the GNU project (begun in 1983 by Richard Stallman).
The term "Linux" is now even applied to whole Linux distributions, which typically bundle large quantities of software, from web servers like Apache HTTP Server to graphical environments like GNOME to office suites like OpenOffice.org, with the core operating system.
Since its initial release, the Linux operating system has experienced rapid growth in popularity, overtaking proprietary software versions of Unix and even beginning to challenge the dominance of Microsoft Windows. It has been deployed in applications ranging from personal computers to supercomputers to Embedded system|embedded devices such as mobile phones, supporting a remarkable variety of computer hardware.
The official logo of Linux is Tux the penguin.
Local Linux User Groups exist as forums for users of Linux-based operating systems in most areas.
The Linux trademark (SN: 1916230) is owned by Linus Torvalds, and is defined as "Computer operating system software to facilitate computer use and operation."